move ethutil helper slice functions -> slice

ethutil/slice.go

+package ethutil
+
+import (
+	"strconv"
+)
+
+// Helper function for comparing slices
+func CompareIntSlice(a, b []int) bool {
+	if len(a) != len(b) {
+		return false
+	}
+	for i, v := range a {
+		if v != b[i] {
+			return false
+		}
+	}
+	return true
+}
+
+// Returns the amount of nibbles that match each other from 0 ...
+func MatchingNibbleLength(a, b []int) int {
+	i := 0
+	for CompareIntSlice(a[:i+1], b[:i+1]) && i < len(b) {
+		i += 1
+	}
+
+	return i
+}